How do I set up to disable access from a certain regional IP, or is there a plugin for that?

Thank you very much for your reply.
I’ve found where the settings are, and it seems that the settings are not having the effect of disabling IP access for this reason. I will look into it again.
I will ban Chinese and Korean ip. because I want to avoid unnecessary trouble. Because China, Korea and Japan have the same skin color and similar aesthetics. I don’t want to attract customers with little connection.

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